Russian forces attacked the steel plant where remaining Ukrainian forces and citizens are sheltering in Mariupol, officials say

Ukrainian officials said that Russian forces invaded a steel plant in Mariupol.

Oleksiy Arestovich, an advisor for the presidential office of Ukraine, told the Associated Press that Russian forces were trying to storm the Azovstal plant on Saturday.

There are at least 1,000 people taking shelter in the underground caverns of the plant.

Russian defense minister Sergei Shoigu told Putin that the rest of Mariupol was under Russian control. At that time, Putin called off the offensive.

He called on the remaining Ukrainian forces to lay down their arms and said Russia would guarantee their lives and treatment.

Major Serhiy Volyna, the commander of the remaining Ukrainian forces, previously told Insider that they wouldn't lay down their arms.

Volyna said that they were not even considering that possibility.

Mariupol has been under siege by Russian forces since February. Over 100,000 people are trapped in the city.

Ukrainian officials said that at least 21,000 people have died in Mariupol. Satellite images show mass grave sites in the towns surrounding Mariupol.

Ukrainian President Volodymyr Zelenskyy has said that negotiations could end if Russia kills Mariupol's remaining forces.